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[目的]筛选对棉花枯萎病菌有拮抗作用的内生菌株。[方法]以采自湖北荆州棉花种植区的新鲜棉花植株为试验材料,对其进行内生菌株的分离,再通过几丁质酶及平板对峙双重筛选对棉花枯萎病菌有拮抗作用的菌株。[结果]从大田棉花植株内分离出83株细菌,其中6株为几丁质酶产生菌。通过几丁质酶及平板对峙双重筛选,从中获得菌株V-8对棉花枯萎病菌(Fusarium oxysporum f.sp.vasinfectum)拮抗作用最强,该菌株具有较宽的抑菌谱,对西瓜枯萎病菌(Fusarium oxysporum f.sp niveum)等6种重要病原真菌均具有一定的抑制作用;在棉花根际土壤能稳定定殖,50d后定殖密度达6.2×105cfu/g;对棉花枯萎病的盆栽防效为73.2%。表明内生细菌V-8对棉花枯萎病的生物防治具有较大的潜力,可作为几丁质酶基因克隆的重要材料。[结论]该研究结果为棉花枯萎病的防治以及充分开发棉花内生菌资源、研制新型生物农药奠定了基础。
[Objective] The research aimed to screen endophytic strains antagonistic to Fusarium oxysporum f.sp. [Method] With fresh cotton plants collected from Jingzhou cotton growing area in Hubei Province as experimental materials, endophytic strains were isolated, and then antagonistic strains against cotton Fusarium oxysporum were selected by chitinase and plate confrontation double screening. [Result] 83 strains of bacteria were isolated from Daejeon cotton plants, of which 6 were chitinase producing bacteria. The results showed that strain V-8 had the strongest antagonistic activity against Fusarium oxysporum f.sp.vasinfectum through chitinase and plate confrontation screening. The strain V-8 had a wide range of antibacterial spectrum against Fusarium oxysporum f.sp.vasinfectum, Fusarium oxysporum f.sp niveum) and other six kinds of important pathogenic fungi all had certain inhibitory effect. The cotton rhizosphere soil could colonize steadily and the colonization density reached 6.2 × 105cfu / g after 50 days. 73.2%. It showed that endophytic bacteria V-8 had great potential for biological control of cotton blight and could be used as an important material for chitinase gene cloning. [Conclusion] The results of this study laid the foundation for the prevention and control of cotton Fusarium wilt, the development of cotton endophyte resources and the development of new biological pesticides.